Keeping your LiFePO4 bank warm for charging in winter- what’s the best?

[s/v Jedi]

Originally Posted by Chotu

Ok. So they used an A-frame concept to lower the mast.

That’s a lot easier than trying to build an A-frame and then raising the mast with it.

However, it’s worth a consideration. The only problem is where do you find a no wake zone that good? Ha ha.

I will think through this though. Maybe it’s OK. But you still have to get all of that wood delivered somehow and find a place to do it. You need to be at a marina for that. So I guess the crane rental is probably cheaper and more simple? Assuming I can find a crane that can reach out over a dock somewhere.

I stepped my mast on a 45ft Gulfstar using a manual crane at Castleton-on Hudson before. It was great. Right at the dock. I think this one is too tall for that crane.

Kind of would like to just go to one place and do all of this. But I have not found that place

But you have a very wide catamaran, much easier than a narrow, rolly, small monohull. You can easily build those A-frames on deck, then raise them. They only need to be a little higher than halfway up the mast.

I spent 17 years on a 30’ monohull with a deck stepped mast in a tabernacle. We used two legs that attach between the forestay turnbuckle and a block and tackle to the forestay chainplate. The trouble is controlling sideways motion which is tough when your shroud chainplates are aft of the mast. But the A-frame would work. How heavy is the mast? It’s nothing.

[Chotu]

Originally Posted by s/v Jedi

Originally Posted by s/v Jedi

But you have a very wide catamaran, much easier than a narrow, rolly, small monohull. You can easily build those A-frames on deck, then raise them. They only need to be a little higher than halfway up the mast.

I spent 17 years on a 30’ monohull with a deck stepped mast in a tabernacle. We used two legs that attach between the forestay turnbuckle and a block and tackle to the forestay chainplate. The trouble is controlling sideways motion which is tough when your shroud chainplates are aft of the mast. But the A-frame would work. How heavy is the mast? It’s nothing.

I do agree with that.

There is the matter of getting all of this wood somewhere and having it delivered somewhere and being able to move it onto the boat when it is delivered.

That requires a marina and a dock. And that’s what makes it not feasible. It’s financially not feasible.

If you are spending $400 wood and ratchets and come alongs and delivery, then working with the attached transient slip rates ($2250 for a week at the dock) to build the frames… but the crane is $375/hr, it’s much less expensive to use the crane.

[Chotu]

I definitely appreciate the outside the box thinking and brainstorming but that one is too expensive. It’s just so much cheaper to use the crane. Way less work also.

I just have to find a place where the crane can reach the boat

[s/v Jedi]

Originally Posted by Chotu

I do agree with that.

There is the matter of getting all of this wood somewhere and having it delivered somewhere and being able to move it onto the boat when it is delivered.

That requires a marina and a dock. And that’s what makes it not feasible. It’s financially not feasible.

If you are spending $400 wood and ratchets and come alongs and delivery, then working with the attached transient slip rates ($2250 for a week at the dock) to build the frames… but the crane is $375/hr, it’s much less expensive to use the crane.

That’s one way to do it, but not the feasible way. To make this work, I would anchor close to a public ramp, go to the Home Depot, rent their pickup truck for $25 to move the lumber and hoist etc. then dinghy them aboard. Zero marina cost, zero delivery fees. And the lumber you can burn in your wood stove to keep warm during the winter, which solves your hauling fuel problem in one go

[Chotu]

Originally Posted by s/v Jedi

That’s one way to do it, but not the feasible way. To make this work, I would anchor close to a public ramp, go to the Home Depot, rent their pickup truck for $25 to move the lumber and hoist etc. then dinghy them aboard. Zero marina cost, zero delivery fees. And the lumber you can burn in your wood stove to keep warm during the winter, which solves your hauling fuel problem in one go

I guess I will look into it, but that wood will need a lot of time and pressure to turn into viable diesel to heat with . Ha ha ha.

[Chotu]

Here’s a pretty interesting option that I have that I didn’t even realize I had.

If I get a dock for the winter, which is likely, I already have a 12 V power supply that I can plug into the shore power:

https://www.iotaengineering.com/prod...ttery-charging

My trusty Iota 90amp converter/charger.

It will be so simple that all I have to do is disconnect the batteries from the circuit after charging them completely, remove the LiFePO4 charge controller from the DLS-90, and I have a steady 13.4VDC at up to 90amps as long as the shore power stays on

Easy!

[sailingharry]

Originally Posted by Chotu

It will be so simple that all I have to do is disconnect the batteries from the circuit after charging them completely, remove the LiFePO4 charge controller from the DLS-90, and I have a steady 13.4VDC at up to 90amps as long as the shore power stays on

Easy!

Seems like a good plan. One objection. The way I understand it, LFP prefer to be stored in a partial state of charge, maybe 50%. And since LFP have a near zero self-discharge rate, if you disconnect them at 50%, they will still be at 50% 4 months later.

[s/v Jedi]

Originally Posted by sailingharry

Seems like a good plan. One objection. The way I understand it, LFP prefer to be stored in a partial state of charge, maybe 50%. And since LFP have a near zero self-discharge rate, if you disconnect them at 50%, they will still be at 50% 4 months later.

Agreed, we store at 50% and only keep one in use during storage (bilge pumps, gray water pump etc.) and only charge that to 70%

We just returned after 3.5 months and found the disconnected batteries exactly like we left them incl. one cheap LiTime with internal BMS.

[Chotu]

Oh yeah. Good point. Thanks for reminding me, guys. I’ll be sure to drop the charge appropriate prior to storage.

I was thinking old FLA thoughts